US 2307193 A
Description (OCR text may contain errors)
Patented Jan. 5, 1943 UNITED STTES v` PATENT OFFICE GOLF CLUB HEAD Geforr L. Beis, Eeho, Wis.
Application April 23, 1941, Serial No. 389,882V
3 Claims. (Cl. 273-77) My invention relates to improvements in golf club heads and methods of forming the same.
Objects of my invention are to provide a golf club head of improved strength, improved striking efficiency, and improved appearance.
More specifically, my objects are to provide a laminated golf club head in which some of the plies extend into the neck or shank portion-in which some of the plies are provided with rubber inserts marginally exposed on the striking face of the club and held under compression by adjacent plies, Whereby to add to the resilience of the striking facein which plies from different tree species may be employed and connected with each other and to the rubber inserts by a thermo setting adhesive, whereby plies of different resistance to tensile, splitting and crushing strains may be made to reenforce each other in such a manner as to produce a substantially indestructible head.
Further objects of my invention are to provide means Whereby the plies may be shaped under heavy pressure so that the grain of the wood will follow a curved line corresponding with the axis of the completed head and shank portions, and whereby superposed plies having such curvature may be cemented together and to the rubber inserts while subject to such pressure to produce a block which may then be turned and finished in a lathe to complete the head.
A further object is to provide means whereby golf club heads of improved appearance may be formed with exposed margins of the plies in different colors and degrees of finish, due to the different kinds of-wood employed and to the mar- I ginal exposure of the rubber inserts on the striking face.
A further object is to provide an improved method of manufacturing golf club heads, whereby they are rendered substantially indestructible -fi even in the shank portion.
In the drawing:
Figure 1 is a perspective View of one of the plies as it appears before steam bending or flexing.
Figure 2 is aview of one of the plies after it has been notched and associated with a rubber insert, fragments of two superposed plies being also illustrated.
Figure 3 is a perspective view of a laminated block composed of plywood, with the plies cemented together, shaped to the curvature of a club head and its shank, and provided with rubber inserts exposed on the striking face.
Figure 4 is a side elevation of the striking face and associated parts of my improved club.
'Z splitting and color characteristics.
Like parts are identified by the same reference characters throughout the several views.
In the practice of my improved method, I form a series of sheet or slab-like plies at least equal in length to that of the body and shank of a golf -club head, and with the grain of the wood running longitudinally. I may also provide a series of shorter plies havinga length and width atv least equal to that of the body of the golf club head, and with margins chamfered or provided with convergent upper and lower surfaces extending in the direction of the shank portion.
I preferably form the plies of different kinds or varieties of Wood, with different breaking, Some of the plies, particularly those which are to extend into the shank of the completed club, are preferably formed of pecan wood, whereas others may be formed, for example, of maple, (preferably birdseye maple), hickory, mahogany, or teak, or any other hard wood of the requisite strength and resistance to splitting tendencies. I
Some of the plies are notched in those margins which are to form the striking face of the club, and when the plies are assembled these notches are filled with sheets of rubber, or equivalent material of relatively high resilience, eachv of slightly greater thickness than the ply to which it is applied. Either before or after assem- :v bly, the end portions wlich are to form the shank are bent upwardly at the proper angle, whereby the grain of the wood in these plies vvill extendl parallel to the aXis of the body and shank por-v tions in the completed club.
l'n assembling the plies, their opposing surfaces and those of the rubber inserts, are covered with a thermoplastic glue or cement, and the assembled plies are then placed in a form andsubjected to heavy and uniform pressure until the glue or cement has set. Suficient pressure should be applied to compress the rubber inserts to the thickness of the plies with Which the v are associated and to bring all surfaces of the associated plies into the most intimate possible contact with each other. Also, while the pressure is being applied, the plies are heated sufiiciently to cause the thermoplastic glue to promptly set. and thereby place the rubber inserts, as well as the plies, under permanent compression.
It is not essential to my invention Whether the plies are initially bent preparatory to assembly by steam pressing them in accordance with ordinary practice, or whether the bending, heating, and compressing operation is simultaneously performed immediately after applying the thermo-plastic cement and assembling the plies.
In assembling the plies, some of the shorter plies may have the grain of the wood running transversely to the striking face of the completed block, i. e., parallel with their chamfered edges, and others may have the grain of the wood running parallel to that of the longer plies and to the striking face of the completed club head.
Also, in assembling the plies, I preferably group the pecan plies in the zone from which the shank is to be formed. The plies composed of other kinds of wood may be assembled individually or in groups in such a manner that the exposed surfaces of the completed head, and particularly of the striking face, will have a striped appearance in contrasting color and finish, characteristic of the respective kinds of wood employed.
After assembling and cementing the plies as 'above described, the block may be turned in a lather or otherwise contoured to the formv of a golf club head and shank, thereby completing the operation.
By using different kinds of wood having different splitting and breaking characteristics, I not only provide variations in color and finish, but I obtain increased strength and durability. The rubber inserts and the notches which receive them are preferably triangular in form, with one margin of the triangle exposed on the striking face. I find that these sheet-like rubber inserts, under permanent compression, add materially to the striking efficiency of the club by reason of their relatively greater resilience as compared with that of the wood. Also, by arranging a few of the short plies with the grain running transversely of the striking face, the possibility of splitting is still further reduced, although, in any event, it is virtually impossible to split or break these laminated club heads or their shanks.
In Figure 1 of the drawing I have illustrated 'a slab IO of plywood of a length slightly greater than that of the head and shank of the completed club, and a width slightly greater than that of the completed body of the club head. In Figure 2 I have illustrated a similar slab IO provided with a` notch ll to receive a sheet-like rubber insert [2. The fragment of a superposed slab 13 is shown with its grain running longitudinally of that in the slab IO, i. e., parallel with the margin IA of the slab IO. I also show a body slab l5 superposed on the slab l3, with its grain running transversely, and with its margin IB chamfered or 'arrised, whereby it may be interposed between the slab l3 and a superposed slab without producing a shoulder and cavlty when the plies are compressed together, as above described.
In the particular assembly indicated in Figure 3, the group of plies ll may be assumed to be pecan plies, those in the group l8 may be assumed to be mahogany plies, those in the group IQ may be of birdseye maple, and those in the group 20 may be of hickory. However, I do not limit the scope of my invention to any particular arrangement of the plies, in groups or otherwise, nor to the use of different kinds of wood for the manufacture of the respective plies.
Also, the inserts may be formed of any suitable elastic material other than rubber, although I prefer to form them of rubber for the reason that its characteristics are well known and the effects can be readily calculated, not only as to striking eficiency, but as to adherence to the plies, and degree of compressibility, whereby the thickness of the. compressed insert may be` calculated and made to conform to the thickness of the ply in the assembled structure.
l. A laminated golf club head having multiple plies with margins exposed and constituting a striking face, the striking marginal portions of some of the plies being provided with V-shaped notches filled with inserts of compressible material having relatively high resilience and of normal thickness greater than that of the plies which receive them and held under permanent pressure to substantially the same thickness as that of the ply.
2. A laminated golf club head comprising the combination of superposed wooden plies cemented together and of such thickness along the striking face as to be maintained in permanent 'and uniform pressure contact with each other, some of said plies extending along curved lines fromthe body into the shank portion of the head and longitudinally of the grain of the wood, and other of said plies being located only in the body, with margins chamfered in the direction of the heel, and with the grain of the wood running transversely, the respective plies being formed from different kinds of wood differing in appearance, strength and resistance to splitting tendencies.
3. A laminated golf club head having its striking face composed in part of superposed wooden and rubber plies of substantially equal thickness cemented and held together under permanent high compression.
GLENFORD L. BELLIS.